Simatic Timer Instructions; On-Delay Timer, Retentive On-Delay Timer, Off-Delay Timer - Siemens SIMATIC S7-200 System Manual

9.3

SIMATIC Timer Instructions

On-Delay Timer, Retentive On-Delay Timer, Off-Delay Timer

L
A
D
IN
F
PT
B
D
IN
PT
IN
PT
S
TON
T
L
TONR
TOF
221 222 224
If the TOF timer is inside an SCR region and the SCR region is inactive, then the
current value is set to 0, the timer bit is turned OFF, and the current value does not
count.
Inputs/Outputs
Txxx Constant
IN (LAD) Power Flow
IN (FBD) I, Q, M, SM, T, C, V, S, L, Power Flow
PT VW, IW, QW, MW, SW, SMW, LW, AIW, T, C, AC, Constant, *VD,
*AC, *LD
S7-200 Programmable Controller System Manual
A5E00066097-02
The On-Delay Timer and Retentive On-Delay Timer
instructions count time when the enabling input is ON.
Txxx
When the current value (Txxx) is greater than or equal to
TON
the preset time (PT), the timer bit is ON.
The On-Delay timer current value is cleared when the
enabling input is OFF, while the current value of the
Txxx
Retentive On-Delay Timer is maintained when the input
TONR
is OFF. You can use the Retentive On-Delay Timer to
accumulate time for multiple periods of the input ON. A
Reset instruction (R) is used to clear the current value of
Txxx
the Retentive On-Delay Timer.
TOF
Both the On-Delay Timer and the Retentive On-Delay
Timer continue counting after the Preset is reached, and
they stop counting at the maximum value of 32767.
The Off-Delay Timer is used to delay turning an output
Txxx, PT
OFF for a fixed period of time after the input turns OFF.
When the enabling input turns ON, the timer bit turns ON
Txxx, PT
immediately, and the current value is set to 0. When the
Txxx, PT
input turns OFF, the timer counts until the elapsed time
reaches the preset time. When the preset is reached, the
timer bit turns OFF and the current value stops counting.
226
If the input is OFF for a time shorter than the preset
value, the timer bit remains ON. The TOF instruction
must see an ON to OFF transition to begin counting.
Operands
SIMATIC Instructions
Data Types
WORD
BOOL
BOOL
INT
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